On Tue, 23 Apr 2002, Trei, Peter wrote:
> As usual, Jim is wrong. There are deterministic systems which never
> repeat. For example, there is an algorithm which will give you the
> nth digit of pi.
Ok. The distribution of a single digit is -not- the same as pi itself...
> If I use this as my PRNG
The -only- thing in question there is the index of the digit you started
with. From there the sequence is ABSOLUTELY deterministic. It's a basic
select and compare problem at that point. pi may be irrational, but its
value is constant. So is the sequence of digits that your algorithm
generates, irrespective of the starting digit -provided- we can ever find
an overlap in the two sequences (your original and my search). There's
been some pretty nifty string manipulation algorithms in the last few
years coupled with some of the new parallel and distributed systems....
Not a very good PRNG, not even as a seed source to a hash function.
Look. Software is nothing more than instructions to -general purpose
computing HARDWARE-. The question is what does that mean when we talk
about -hardware-? The hardware that my computer runs on is binary. And it
uses some derivation of at least two of three basic functions (ie NOT,
AND, OR). If I can't write it in software which is simply commands to
specific meshes of these basic gates (assuming of course the two meshes
can be made comparable - cost v complexity) execute specific sequences of
operations on specific bits of data. Now we take out the abstraction layer
that the -general purpose- throws in there. We take that program and build
it using the -exact- same sort of logical gate meshes. What changed?
Nothing. That's the -universal- in 'Universal Turing Machine'. What is the
-primary- dependency of the UTM? That it is -binary-.
-If- you want to do a -real- RNG then it must have some -continous-
component and include some sort of feedback(forward) dependency.
The strength of hardware comes from the fact that you can do things that
aren't representable in some other languages (eg Boolean Algebra), A/D <>
D/A conversion, dependencies on manufacturing tolerances, etc.). Those
come from the -analog- characteristic of the -representation- of the logic
in hardware. It's a -hidden- variable, so to speak.
--
____________________________________________________________________
The law is applied philosophy and a philosphical system is
only as valid as its first principles.
James Patrick Kelly - "Wildlife"
[EMAIL PROTECTED] www.ssz.com
[EMAIL PROTECTED] www.open-forge.org
--------------------------------------------------------------------
